The invention is directed to a process for the production of thiazoline-(3) compounds from oxo compounds, sulfur compounds and ammonia. Thiazoline-(3) compounds serve as oxidation inhibitors for polyolefins. They are also starting materials for the production of sulfur containing amino acids such as cysteine and penicillamine.
It is known to produce 2,5,5-trialkyl substituted thiazoline-(3) compounds by reacting alkylidene vinyl amines with sulfur (Schade German Auslegeschrift No. 1,063,602), or by reaction of an aldehyde branched on the .alpha.-carbon atom with sulfur and ammonia (German Offenlegungsschrift No. 1,795,299 and related Asinger U.S. Pat. No. 3,700,683). It is also known that thiazoline-(3) compounds having alkyl substituents in the 2, 4 and 5 positions are formed by reacting ketones which have at least one hydrogen atom in the .alpha.-position to the oxo group with sulfur and ammonia (Asinger, Angewandte Chemie, International Edition 6 (1967) 907-919, particularly page 908). This process in some cases only results in moderate yields. Besides, according to this process only certain thiazoline-(3) compounds can be recovered. Thiazolines which are not substituted in the 2- or 5-position or in 2-, 4- or 5-position are not accessible by this process.
Besides, it is known to produce thiazoline-(3) in a given case substituted in the 2, 4 and 5 positions by reaction of .alpha.-mercaptoaldehydes, .alpha.-mercaptoketones or S-acetylated .alpha.-mercaptoketones with oxo compounds and ammonia (Asinger, Angewandte Chemie, loc. cit., particularly pages 909 to 910). There are produced thiazoline-(3) compounds, in a given case substituted in the 2, 4 and 5 positions from 2,2-dioxodisulfides, oxo compounds, ammonia and hydrogen sulfide (Asinger U.S. Pat. No. 3,004,981) or there are produced 2 and 5 position substituted thiazoline-(3) compounds by such process (Offermanns German OS No. 2,254,701 and related Offermanns U.S. Pat. No. 3,931,208). The disadvantage of this process is that it is required starting materials which are not readily accessible.